We report on the discovery of a new outcrop of fossiliferous Neogene sediments on northern James Ross Island, northern Antarctic Peninsula. Approximately 100 specimens of the pectinid bivalve Austrochlamys anderssoni (Hennig, 1911) were collected from the permafrost active layer. This bivalve species has a late Miocene to late Pliocene range and has previously been reported from both the glaciomarine Hobbs Glacier Formation and the interglacial Cockburn Island Formation in the James Ross Island area. The localized presence of abundant A. anderssoni within the permafrost suggests that the fossils have been frost heaved from an outcrop of either the Cockburn Island or the Hobbs Glacier formations, originally deposited on northern James Ross Island. The overall shell form, general absence of associated Antarctic Peninsula-derived clasts in the host sediment, and the measured 87Sr/86Sr isotope ratio of the shells (0.709050) which is indistinguishable from that for pectinid bivalves from the Cockburn Island Formation on Cockburn Island (0.709047) suggest that the shells were derived from a unit similar in age to the Cockburn Island Formation. This suggests that the Cockburn Island Formation was originally more laterally extensive than was previously known.

The circulation and water masses of Port Foster, Deception Island, were studied using conductivity-temperature-depth stations inside and outside the semi-enclosed bay and an array of bottom temperature sensors moored around the perimeter of the bay over two weeks in the summer of 2012. Inside Port Foster, the water column is divided into two layers separated by a temperature-forced, seasonal pycnocline at ~40–60 m. The circulation of the upper layer is in an anticlockwise direction, with mean geostrophic currents of ~0.04–0.10 ms-1. The lower layer, from ~60 m to the seabed, shows coastal-trapped waves travelling in a clockwise direction, possibly triggered by local wind gusts. Local sea ice melt in areas surrounding the underwater hot springs of Pendulum Cove appears as a fresh, warm anomaly down to 30 m.

To understand the adaptability to environmental stresses by Deschampsia antarctica, one of the two vascular plants growing in Antarctica, we analysed the activity of several antioxidant enzymes, including peroxidase (POD, EC 1.11.1.7), ascorbate peroxidase (APX, EC 1.11.1.11), catalase (CAT, EC 1.11.1.6)) and glutathion reductase (GR, EC 1.6.4.2), in shoots subjected to drought stress (PEG-8000, -0.3 MPa). Additionally, levels of total phenolic compounds, flavonoids and ascorbate, were determined. The content of malondialdehyde (MDA), chlorophyll and hydrogen peroxide did not change as a result of PEG-8000 treatment. In addition, treated plants showed higher enzymatic activity of CAT, POD and GR in shoots than control plants. In addition, a high capacity to scavenge free radicals was also detected in stressed plants. These results seem to indicate that in D. antarctica tolerance of drought stress is associated with enhanced activity of antioxidant enzymes and free radical scavenging capacity.

A fossil hydrothermal system on Barton Peninsula, King George Island, Antarctica, formed a series of lead-zinc- and pyrite + native sulphur-bearing epithermal quartz ± calcite veins, filling fault-related fractures in hydrothermally altered volcanic rocks of Eocene age. The lead-zinc veins occur within argillic hydrothermal alteration zones, whereas the pyrite + native sulphur veins are found within advanced argillic alteration zones. Fluid inclusion data indicate that the vein formation occurred at temperatures between about 125° and 370°C (sphalerite deposition formed at 123–211°C) from fluids with salinities of 0.5–4.6 wt.% eq. NaCl. Equilibrium thermodynamic interpretation of mineral assemblages indicates that the deposition of native sulphur in the upper and central portions of the hydrothermal system was a result of the mixing of condensates of ascending magmatic gases and meteoric water giving rise to fluids which had lower pH (<3.5) and higher fugacities of oxygen and sulphur than the lead-zinc-depositing fluids at depth. The δ34S values of sulphide minerals from the lead-zinc veins (δ34S = −4.6 to 0.7‰) are much higher than the values of pyrite and native sulphur from the pyrite + native sulphur veins (δ34S = −12.9 to −20.1‰). This indicates that the fluids depositing native sulphur had higher sulphate/H2S ratios under higher fo2 conditions. Sulphur isotope compositions indicate an igneous source of sulphur with a δ34SΣS value near 0‰, probably the Noel Hill Granodiorite. Measured and calculated δ18O and δD values of the epithermal fluids (δ18Owater = −6.0 to 2.7‰, δDwater = −87 to −75‰) indicate that local meteoric water played an important role for formation of lead-zinc and native sulphur-bearing quartz veins.

Amphipod crustaceans constituted 30% of the food biomass from the stomachs of Antarctic tern (Sterna vittata) captured at King George Island in three consecutive seasons. Five species of lysianassoid amphipods occurred in the material: Abyssorchomene plebs, Cheirimedon femoratus, Hippomedon kergueleni, Waldeckia obesa and Orchomenella rotundifrons. All these amphipods are known as necrophages inhabiting the upper and middle sublittoral of western Antarctic. They are commonly caught in masses in baited traps, but never occur in the littoral zone or in tidal pools. It is suggested that the source of the amphipod diet of S. vittata are seal or penguin carcasses and dead fish brought by waves to the tidal zone, serving as a bait for necrophagous amphipod crustaceans when submerged in water before stranding on the beach.

Age, growth and feeding habits of early life stages of Chionodraco rastrospinosus Dewitt & Hureau, the most abundant channichthyid in the larval fish assemblages of the Bransfield Strait, were studied by otolith microincrement counts and stomach content analyses. Individuals measuring 39–69 mm standard length were caught in the uppermost depth strata down to 300 m from Brabant to Joinville islands along the northern Antarctic Peninsula. The sample consisted of post-larvae and juveniles aged 105–211 days, with a mean growth rate of 0.25 mm day-1. Larval size at hatching was estimated to be c. 17.2 mm. Hatching was spread over a relatively long period from August–November. Sagittal otoliths were characterized by a strong check located at 23–52 microincrements of distance from the core, tentatively associated with the onset of first exogenous feeding. The relatively long period during which larvae can rely on yolk reserves and the large size at hatching enable them to utilize a wide size range of prey, as well as cope with occasional food shortages. The stomach contents consisted exclusively of euphausiids (furcilia and adults) and larvae of Pleuragramma antarcticum Boulenger. Based on growth rate, the residence time in pelagic waters of juvenile C. rastrospinosus was estimated to be about a year and a half.

For most parts of the year the Antarctic Plateau has a surface temperature inversion with strength c. 20 K. Under such conditions the warmer air at the top of the inversion layer contributes more to the clear sky atmospheric longwave radiation at surface level than does the colder air near the ground. Hence, it is more appropriate to relate longwave irradiance (LWI) to the top of the inversion layer temperature (Tm) than to the ground level temperature (Tg). Analysis of radio soundings carried out at Dome C and South Pole during 2006–08 shows that the temperature at 400 m above the surface (T400) is a good proxy for Tm and is linearly related to Tg with correlation coefficients greater than 0.8. During summer, radiosonde measurements show almost isothermal conditions, hence T400 still remains a good proxy for the lower troposphere maximum temperature. A methodology is presented to parameterize the clear sky effective emissivity in terms of the troposphere maximum temperature, using ground temperature measurements. The predicted LWI values for both sites are comparable with those obtained using radiative transfer models, while for Dome C the bias of 0.8 W m-2 and the root mean square (RMS) of 6.2 W m-2 are lower than those calculated with previously published parametric equations.

The small ice-free areas of Antarctica provide an essential habitat for most evident terrestrial biodiversity, as well as being disproportionately targeted by human activity. Visual detection of disturbance within these environments has become a useful tool for measuring areas affected by human impact, but questions remain as to what environmental consequences such disturbance actually has. To answer such questions, several factors must be considered, including the climate and biotic and abiotic characteristics. Although a body of research has established the consequences of disturbance at given locations, this paper was conceived in order to assess whether their findings could be generalized as a statement across the Antarctic continent. From a review of 31 studies within the Maritime Antarctic, Continental Antarctic and McMurdo Dry Valleys regions, we found that 83% confirmed impacts in areas of visible disturbance. Disturbance was found to modify the physical environment, consequently reducing habitat suitability as well as directly damaging biota. Visible disturbance was also associated with hydrocarbon and heavy metal contamination and non-native species establishment, reflecting the pressures from human activity in these sites. The results add significance to existing footprint measurements based on visual analysis, should aid on-the-ground appreciation of probable impacts in sites of disturbance and benefit environmental assessment processes.

This study examined high temperature survival and heat shock protein 70 (Hsp70) responses to temperature variation for two marine invertebrate species on sub-Antarctic Marion Island. The isopod Exosphaeroma gigas Leach and the amphipod Hyale hirtipalma Dana had the same tolerance to high temperature. The mean upper temperature which was lethal for 50% of the population (upper lethal temperature, ULT50) was 26.4°C for both species. However, the isopod E. gigas showed significant plasticity of ULT50, with a positive response to acclimation. In addition, the isopod had a heat shock response of Hsp70 at all acclimations, and the amount of Hsp70 protein increased significantly from basal levels upon an acute warm exposure after a cold acclimation. By contrast, the amphipod H. hirtipalma showed limited plasticity of ULT50 and no evidence for a heat shock response (failure of three different Hsp70 antibodies to bind to the extracted 70kDa proteins). Overall, these results reflect different flexibility of thermal tolerance of intertidal invertebrate species on Marion Island, with possible variation in the underlying cellular mechanisms, suggesting that warming associated with climate change may result in changes in species assemblage structure in sub-polar environments.

The Indian Institute of Geomagnetism (IIG) in 1982, 1986, and 1996, operated a Proton Precession Magnetometer (PPM) at its Antarctic stations Dakshin Gangotri/Maitri (located at ∼70°S, ∼12°E). Comparison of the average quiet-time value of total intensity F for these years with values of F obtained at the same geographic location (interpolated from iso-intensity contours of F on World Magnetic Charts and IGRF Maps) for earlier years, suggested that over the last 75 years at this location, F has dropped from ∼49 000 nT in 1922, to ∼40 000 nT in 1996 i.e. ∼120 nT per year. Further inspection at nearby Antarctic stations reveals a drop of ∼108 nT yr−1 at Novolazarevskaya, ∼100 nT yr−1, at Georg Forster and ∼95 nT yr−1 at Syowa; Mawson situated still further away shows a drop of ∼72 nT yr−1, while Dumont d'Urville located very near the magnetic pole showed a drop of ∼50 nT yr−1 until 1994. A study of the observed F values over the past five decades at 23 observatories from the Antarctic and sub-Antarctic regions indicates that contours of yearly decrease in F follow a definite pattern, with maximum decrease lying in a belt encompassing Maitri. These observations are of importance in the light of modelling works at the Earth's Core–Mantle boundary pointing to two prominent regions of reverse magnetic flux (RMF) occurring beneath South America, South Africa and a large part of Antarctica, and which may merge sometime to cause reversal of the present geomagnetic field polarity. The importance of continuous monitoring of F at various locations in Antarctic and sub-Antarctic regions is brought out in this work. It is equally important to understand the cause behind this rapid decrease in F.

The design of a computer-controlled climatic simulation cabinet used for mechanical weathering studies on Antarctic rocks is described. It is argued that if the results of simulations are to be applicable to field situations they should be firmly based on field environmental conditions. Some weathering results from a laboratory simulation based upon microclimatic data collected from the maritime Antarctic are presented and it is shown that they could not have been obtained from field measurements alone. Further simulation studies are required for the Antarctic and it is argued that the nature of Antarctic research is such that it is particularly conducive to this type of approach.

The East Antarctic Craton contains only one substantial outcrop of Palaeozoic–Mesozoic strata between 0° and 150°E; this lies in Mac. Robertson Land, on the eastern margin of the northern Prince Charles Mountains. These rocks are known as the Amery Group (Mond 1972, McKelvey & Stephenson 1990) and comprise dominantly fluviatile sandstones, with subordinate shales, coals and conglomerates. The lower formations of the Amery Group, the Radok Conglomerate and Bainmedart Coal Measures, contain a diverse Stage 5 palynomorph assemblage indicating a Baigendzhinian–Tatarian age (late Early–Late Permian, hereafter abbreviated as mid–Late Permian; Dibner 1978).

We measured the hydrogen and oxygen isotope composition (δ2H and δ18O) of precipitation and stream water from the Soft Plume River at multiple spatiotemporal scales on sub-Antarctic Marion Island, Indian sector of the Southern Ocean. Monthly precipitation δ2H and δ18O values ranged from -43.7‰ to -14.7‰ and from -7.0‰ to -3.3‰ (n=13), respectively. Stream water values ranged from -48.0‰ to -25.4‰ for δ2H and from -7.6‰ to -4.0‰ for δ18O (n=92). The monthly precipitation data yielded a local meteoric water line with the equation δ2H=8.4δ18O+11.4. There was no clear seasonality in isotope composition present in precipitation and stream water. Along the stream, no significant difference was observed between sites. However, δ2H and δ18O values were lower and more variable at the highest site. This is probably the result of the ‘amount effect’, where more precipitation fell at a higher elevation compared with a downstream site in the catchment. The findings illustrate spatiotemporal patterns in precipitation and stream water isotopes and provide insight into mechanisms affecting their composition on sub-Antarctic Marion Island.

New petrographic and geochemical insights from inoceramid bivalve shells of lower Campanian (Marambio Group, James Ross Basin, Antarctica) show that they suffered significant palaeoenvironmental stress just before their disappearance in the southern high latitudes. Inoceramid data have mainly been derived from shell fragments of the large form Antarcticeramus rabotensis Crame & Luther, collected at stratigraphical levels marking the early disappearance of inoceramids in the James Ross Basin (10 m.y. before the Cretaceous/Tertiary boundary in Antarctica). Cathodoluminescence studies and minor and trace element intra-shell variations in A. rabotensis shells, along with their whole shell geochemistry (major, minor, and trace elements, including REE), have revealed evidence of only weak diagenesis but significant palaeoenvironmental stress. The most relevant evidence of such adverse palaeoenvironmental conditions in A. rabotensis shells is reflected by marked growth interruptions in the normal shell layering, including the occurrence of a previously undetected inner aragonitic nacreous layer formed of alternating aragonitic and calcitic sublayers. The weak diagenesis produced characteristic geochemical intra-shell variations, which have subsequently been detected in the inoceramid shell microstructure, especially in the inner aragonitic nacreous layer.

A dynamic-thermodynamic sea ice model is used and coupled with an atmospheric general circulation model to simulate the seasonal cycle of the global sea ice distribution. We have run the coupled system and obtain a creditable seasonal simulation of the Antarctic sea ice. To understand the role of ice advection on the seasonal cycle of Antarctic sea ice in the coupled system, results from the thermodynamiconly (T) sea ice model have been compared with those from the dynamic thermodynamic (DT) sea ice model. The seasonal cycle of sea ice differs between the two models. When ice motion is eliminated sea ice becomes more compact and thinner, and sea ice is more extensive in summer. A number of previous studies have examined the effect of ice dynamics on sea ice simulations with prescribed atmospheric conditions. Here experiments have been performed with a fully coupled atmosphere sea ice system and also using prescribed daily atmospheric forcing and monthly mean atmospheric forcing, to examine the differences of the sensitivity of the ice advection between the coupled and forcing models. Similar differences have been observed between DT and T in the forcing models but the magnitude is smaller than in the fully coupled model, and with monthly mean atmospheric forcing the difference is least. These differences highlight the importance of the inclusion of ice advection when undertaking studies using a fully interactive atmosphere sea ice model, or using prescribed daily/monthly atmospheric conditions to force a sea ice model for the Antarctic.

The necessity for uniform reference systems for conventional maps (analogue) and geographic information systems (digital) is discussed. It is recommended that the following scales and projections are used for Antarctic maps: general maps at scales smaller than 1:1 000 000 should use a stereographic projection. Maps up to a scale of 1:1 000 000 should be compiled according to the specifications of the International Map of the World (IMW) 1:1 000 000. Ellipsoids are used as reference surfaces for the various map projections. Differences of the ellipsoidal parameters of the WGS72 and WGS84 systems have to be considered if accuracies better than 10 m are required. Geographic information systems may store data in vector or raster format and in geographic or in geodetic coordinates. For a raster format which is referred to the geographic (spheroidal) grid the term of ‘geographic raster’ is introduced, in contrast to the ‘geodetic raster’ which is referred to a plane cartesian coordinate system. The Institut für Angewandte Geodäsie (IfAG) is establishing the ‘Geocoded Information System Antarctica’ (GIA) using digital satellite image recordings. Internal storage of data in the GIA is in the form of the geodetic raster (and not by spheroidal coordinates). For the scale range 1:250 000 to 1:1 000 000 the size of the raster element is 60 m × 60 m. For smaller scales, satellite image data of a raster width of 240 m × 240 m are preferred.

‘All cartographers' trouble began with the abolition of the flat-Earth theory ’

Vertical displacements of emerged land caused by oceanic tidal loading are of the order of several tens of millimetres in polar regions. They constitute a long wavelength signal, the amplitude of which is comparable to elevation changes that might be associated with climate-driven changes in ice-sheet volume. Using bilinear interpolation on a 1° by 1° global grid, we examine the amplitudes and phases of vertical displacements caused at any given epoch by the eight most important ocean tide constituents of recent ocean tide models, extrapolated to high latitudes. This permits estimation of the oceanic tidal loading corrections to measurements made by a satellite altimeter along the satellite ground track. We have done so systematically over Antarctica, for a scenario flight of ICESAT, which carries the Geoscience Laser Altimeter System (GLAS), whose primary science goal is to monitor ice-sheet mass balance. Ocean loading tide corrections near the coast of Antarctica can reach several centimetres; overall they average about 10 min.

The land-fast ice and the platelet ice layer off Adélie Land are inhabited by a dense and diversified diatom community. Along with Bacillariophyceae, Archaeomonadaceae sensu Deflandre are present and relatively abundant. These modern siliceous nanostructures are similar to the nanofossils described by geologists in marine sediments from upper Cretaceous to Pliocene, Pleistocene and recently in Holocene and modern sediments, and are probably related to chrysophyte cysts. The two most abundant taxa were Achaeomonas cf areolata Deflandre and Litheusphaerella cf spectabilis Deflandre. The other taxa were not common. Despite the taxonomic uncertainty of immature forms, the diversity of archaeomonads was high. Three new species of Archaeomonas are described. The morphology of A. cf areolata is highly variable, showing a possible diversification over geologic time. Litheusphaerella cf spectabilis also shows some differences between fossil and modern specimens. Recent studies confirm that archaeomonads are extant in diverse marine water bodies and recent sediments. There is growing evidence that these siliceous structures represent possible reliable proxies of sea ice extent, even if their presence in geologic time is not always linked exclusively to sea ice. Further studies are needed to elucidate the exact origin of these cysts and their real taxonomic affinities.

Modern baleen whales (Mysticeti), the largest animals on Earth, arose from small ancestors around 36.4 million years ago (Ma). True gigantism is thought to have arisen late in mysticete history, with species exceeding 10 m unknown prior to 8 Ma. This view is challenged by new fossils from Seymour Island (Isla Marambio), Antarctica, which suggest that enormous whales once roamed the Southern Ocean during the Late Eocene (c. 34 Ma). The new material hints at an unknown species of the archaic mysticete Llanocetus with a total body length of up to 12 m. The latter is comparable to that of extant Omura's whales (Balaenoptera omurai Wada et al. 2003), and suggests that gigantism has been a re-occurring feature of mysticetes since their very origin. Functional analysis including sharpness and dental wear implies an at least partly raptorial feeding strategy, starkly contrasting with the filtering habit of living whales. The new material markedly expands the size range of archaic mysticetes, and demonstrates that whales achieved considerable disparity shortly after their origin.

Changes in adult weight, lipid and fatty acid composition per lipid class were studied over a complete seasonal cycle in Drepanopus pectinatus Brady. This copepod displayed a strong seasonality in adult individual weight and total lipid content. Stages C3 to adult from a summer cohort were compared in terms of lipid and fatty acid structure. Changes in lipid content were related to wax esters and polar lipids (PL) while triacylglycerols (TAG) and cholesterol remained minor constituents except at the end of winter. Changes in fatty acid composition of different lipid classes showed that food limitation in winter was high enough to affect 22:6n-3 (DHA) content in PL, and provoke accumulation of maximal percentages of bacterial marker as branched acids. Composition of TAG followed closely the changes in trophic interactions as diatom and flagellate markers dominated in spring and summer while bacterial and detritus particle markers dominated in late winter. The composition of wax esters followed the same seasonal succession but with a lower level of turn over time and shifted characteristics (bacterial markers) from winter to spring individuals when compared to TAG. Ontogenetic changes showed high triacylglycerols content in younger C3 stages and increasing wax esters with increasing developmental stages. Fatty acid composition of PL showed low percentages of EPA and DHA in stage C3, and recovery of high levels of DHA for stage C4 or 20:5n-3 (EPA) at stage C5. The same trend was observed for 18:4n-3. The reverse pattern was noted for the n-6 polyunsaturated acids (PUFA) suggesting a greater requirement in younger stages. Fatty acid partitioning between neutral and PL suggested essential fatty acids selective incorporation from neutral classes into membrane lipids.